<template>
    <form class="validate-form-container">
        <slot name="default"></slot>
        <div class="submit-area" @click.prevent="submitForm">
            <slot name="submit">
                <button type="submit" class="btn btn-primary">提交</button>
            </slot>
        </div>
    </form>
</template>

<script lang="ts">
import { defineComponent, onUnmounted } from 'vue'
import mitt from 'mitt'
type ValidateFunc = () => boolean
type Events = {'form-item-created': ValidateFunc}
// 实例化 mitt
export const emitter = mitt<Events>()

export default defineComponent({
    emits: ['form-submit'],
    setup(props, context) {
        let funcArr: ValidateFunc[] = []

        const submitForm = () => {
            // 循环执行数组 得到最后的验证结果
            const result = funcArr.map(func => func()).every(result => result)
            context.emit('form-submit', result)//将结果发送出去
        }
        // 将监听得到的验证函数都存到一个数组中
        const callback = (func: ValidateFunc) => {
            funcArr.push(func)
        }
        // 添加监听,接收发送过来的验证结果并将结果添加到funcArr中
        emitter.on('form-item-created', callback)
        onUnmounted(() => {
            emitter.off('form-item-created', callback)
            funcArr = []
        })
        return {
            submitForm
        }
    }
})
</script>

